The invention relates in general to missiles and in particular to a new and useful missile or projectile for use with rapid firearms and having a rotating band around the body of the missile.
U.S. Pat. No. 2,996,012 discloses a projectile body having a recess in its rear end portion, comprising circular grooves and intermediate ribs: The ribs are given a substantially trapezoidal cross section by radial pressure. The radial boundary walls of the recess are undercut to conform to the ribs. On their head portions, the intermediate ribs are axially knurled. The plastic rotating band is injected into the recess thus shaped. An operation of undercutting the intermediate ribs is advantageously avoided in this prior art design. Further, the design is suitable also for broad plastic rotating bands. What is disadvantageous is that an undercut shape can be obtained according to the reference only by upsetting or squeezing under high pressures. This results in an only small deformation of the intermediate ribs, and the rotating band has little hold in the recess. Also, according to the reference, the shape of the intermediate ribs is always symmetrical so that the arrangement may be suitable only for conditions with discharge loads having a preferential direction.
The life of the gun barrel is extended if plastic is used for the rotating band of the ammunition. The anchoring of the plastic rotating band to the projectile body is therefore very important. On the one hand, the rotating band must be prevented from peeling off or getting loose and on the other hand, the solution must be easy and inexpensive to manufacture.